Dihydroxyphenyl compounds and glucoside compounds thereof

ABSTRACT

The present invention is a compound represented by the following formula (1) or (2):                  
 
where one of R 1  and R 2  is hydrogen and the other one is hydrogen or glucose residue. The compound is effective for reforming obese constitution, suppressing or preventing obesity. It is also effective for skin whitening.

FIELD OF THE INVENTION

The present invention relates to dihydroxyphenyl compounds and glucosidecompounds thereof which are useful to reform obese constitution bypromoting shrinkage of general or topical fat tissues, or to suppress orprevent obesity by preventing the fat tissue from swelling.

The present invention relates also to dihydroxyphenyl compounds andglucoside compounds thereof which are effective for skin whitening.

DESCRIPTION OF THE PRIOR ART

Intercorporal fat is neutral fat present in white adipose tissuesproduced from surplus energy intake remaining after energy consumption.Obesity due to heavily accumulated intercorporal fat is not onlyaesthetically unfavorable, but also causes various diseases, such asarteriosclerosis. Recently, more and more people suffer from obesity dueto excessive eating, lack of exercise, and/or stress. On the other hand,a slim and tight body is yearned for particularly by women from theviewpoint of appearance. Accumulation of subcutaneous fat is unfavorablefor health, so that reduction of the fat or prevention of theaccumulation thereof is important.

Meanwhile, capsaicin contained in Capsicum is known to be capable ofpreventing obesity by bonding to blood albumin and secreting hormonewhich promotes adrenal metabolism and activates energy metabolism inlever or fat cells (Kazuo Iwai and Nobuji Nakatani, Function of SpiceIngredients in Foods, 97(1989), Koseikan, Tokyo). However, capsaicin isstrongly irritant and thus has limited applications or is used in alimited amount.

The present inventors speculated that it is difficult to diminishaccumulated fat cells, but it is easier to make the cells smaller bydecomposing lipid droplets in the cells.

The lipid droplet can be decomposed with an enzyme, phospholipase C, ina similar manner as protein. However, it is surrounded by a hydrophobicphospholipid membrane, so that the enzyme present in endoplasmicreticulum which is a mass of water cannot obtain access to the lipiddroplet.

Meanwhile, sympathetic nerves are activated by taking exercise tosecrete fat decomposing hormone. This hormone is believed to remove thephospholipid membrane to allow the enzyme to obtain access the lipiddroplets to thereby promote lypolysis. Therefore, the present inventorsendeavored to find a substance which promotes accessibility of theenzyme to the lipid droplets in a similar manner as the hormone.

As a result, the present inventors found that raspberry ketone,zingerone and derivatives thereof promote decomposition of fataccumulated in fat tissues and, thus, are effective to suppress obesityor to reform obese constitution (Japanese Patent Application Laid-openNo. 2000-169325). However, both raspberry ketone and zingerone havetheir peculiar odor and taste and consequently their amounts of dosageand versatility are limited.

Thus, a lypolysis promoter, skin cosmetic composition, and food or drinkcomposition which have satisfactory versatility and an effect ofpreventing formation of or reducing subcutaneous fat are desired.

Meanwhile, there is strong desire for white skin and, accordingly, it isdesired to prevent or lighten erythema, melanization, stains, orfreckles due to skin damages caused by UV light. To lighten the damagecaused by UV light leads to suppressing photo-aging which causeswrinkles. Thus, a skin cosmetic composition having effects of preventingerythema and of whitening is desired.

In view of the above discussion, it is an object of the presentinvention to provide a substance which is effective for reforming obeseconstitution by promoting shrinkage of general or topical fat tissues,or suppressing or preventing obesity by preventing swelling of the fattissues, and which substance has no odor or taste and has excellentversatility.

Another object of the present invention is to provide a skin cosmeticcomposition which has an excellent whitening effect.

SUMMARY OF THE INVENTION

The present inventors have found that a compound represented by thefollowing formula (1) or (2):

where one of R¹ and R² is hydrogen and the other one is hydrogen orglucose residue, is effective for reforming obese constitution orsuppressing or preventing obesity by promoting lypolysis and haswhitening effect to thereby attain the aforesaid objects.

Thus, the present invention is a compound represented by the formula (1)or (2).

Further, the present invention is a lipolysis promoter or amelanogenesis inhibitor represented by the formula (1) or (2). Stillfurther, the present invention is a skin cosmetic composition or a foodor drink composition comprising the compound represented by the formula(1) or (2).

Also provided is a method for reducing a body weight by orally dosing orapplying to skin the lyolysis promoter represented by the formula (1) or(2).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a GC-MS total ion chromatogram (top) and a mass spectrum(bottom) of 4-(3′,4′-dihydroxyphenyl)-butane-2-one of the presentinvention.

FIG. 2 shows a ¹³C-NMR spectrum of4-(3′,4′-dihydroxyphenyl)-butane-2-one of the present invention.

FIG. 3 shows a GC-MS total ion chromatogram and a mass spectrum of4-(3′,4′-dihydroxyphenyl)-butane-2-ol of the present invention.

FIG. 4 shows a ¹³C-NMR spectrum of 4-(3′,4′-dihydroxyphenyl)-butane-2-olof the present invention.

FIG. 5 shows a ¹H-NMR spectrum of 4-(3′,4′-dihydroxyphenyl)-butane-2-olof the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will be explained in detail.

Japanese Patent Application No.11-42937 by the present applicant waspublished on Sep. 5, 2000(JP Laid-open No. 2000-239143), which describessome species of the present compound as an active ingredient for a skincosmetic composition having melanogenesis inhibition effect.

The compound of the aforesaid formula (1) wherein R¹ and R² are bothhydrogen, 4-(3′,4′-dihydroxyphenyl)-butane-2-one, may be easily preparedby the method described in the above application. Specifically, it maybe easily prepared by cleavage of C—O bond of methylether of zingerone,[4-(3′-methoxy-4′-hydroxyphenyl)-butane-2-one], which is contained inginger, in a known manner with, for example, boron tribromide orhydriodic acid.

The compound of the formula (1) wherein R¹ or R²is glucose residue maybe obtained by extracting it from plants, such as raspberries, with anappropriate solvent and, if necessary, condensing or evaporating thesolvent to dryness in a known method(see Phytochemistry, Vol. 29, No.12,3853–3858(1990)). Alternatively, it may be prepared by condensing3,4-dihydroxy benzaldehyde with acetone and reducing the condensate by aconventional method.

The compound of the aforesaid formula (2) wherein R¹ and R² are bothhydrogen, 4-(3′,4′-dihydroxyphenyl)-butane-2-ol, may be prepared in asimilar manner as described above, starting from4-(3′-methoxy-4′-hydroxyphenyl)-butane-2-ol obtained by reducingzingerone with sodium borohydride. It may also be prepared by reducingthe compound of the formula (1) by a conventional method.

The compound of the formula (1) or (2) may be used alone or incombination of two or more of them as a lypolysis promoter or awhitening agent. An amount of the present compound to be incorporated ina skin cosmetic composition or a food or drink composition intended tobe used for reducing weight may vary depending on the form of thecomposition. In the skin cosmetic composition for reducing weight, thepresent compound is incorporated preferably in an amount of from 0.001to 20 wt %, more preferably from 0.01 to 5.0 wt %, most preferably from0.05 to 3.0 wt % based on the weight of the composition. In the food ordrink composition for reducing weight, the present compound isincorporated preferably in an amount of from 0.001 to 20 wt %, morepreferably from 0.01 to 10.0 wt %, most preferably from 0.01 to 3.0 wt %based on the weight of the composition. If the amount is less than theaforesaid lower limit, an effect of the present invention may not beattained. If the amount is more than the aforesaid upper limit, theeffect may not increase correspondingly. In askin cosmetic compositionwith a major purpose of whitening, the present compound is incorporatedpreferably in an amount of from 0.01 to 5 wt % based on the weight ofthe composition.

In the present skin cosmetic composition, any known substances can beincorporated in addition to the aforesaid present compounds, forexample, those conventionally used in a skin cosmetic composition suchas fats and oils, pigments, surfactants, humectants, UV absorbers,anti-inflammatories, fungicides, antiseptics, and colorants;β-adrenaline action stimulants, such as butopamine and isoproterenol;α2-adrenaline action depressants such as yohimbine and ergotoxine;xanthine derivatives, such as theophylline and caffeine; bipyridinederivatives, such as milrinone and amrinone; and those which suppress orprevent obesity, such as raspberry ketone and zingerone.

In the present food or drink composition, any known substances can beincorporated in addition to the aforesaid present compounds, forexample, those conventionally used in a food or drink composition, suchas saccharides, perfumes, emulsifiers, milk products, proteins,stabilizers, colorants, acidulants, fats and oils, cereals, eggs, gumbase; xanthine derivative such as caffeine; hydroxy citric acid; andthose which suppress or prevent obesity, such as capsaicin, raspberryketone, zingerone and synephrine.

The present lypolysis promoter can be incorporated in food, oral drugs,or skin cosmetics in any dosage form. For example, the skin cosmeticsfor reducing weight may be of a form of cream, milky lotion, gel, stick,sheet, cataplasm, powder, liquid or granule to be applied to skin, forbathing, or for washing. The food or drink composition may beincorporated in chewing gum, chocolate, candies, gummy jellies, soup,ice cream, noodles, or bakery products.

EXAMPLES

The present invention will be explained in details with reference to thefollowing Examples and Comparative Examples. Efficacy of lypolysispromotion was evaluated in the lypolysis test and in the subcutaneousfat decomposition test described below. Commercially available raspberryketone and zingerone were used.

Preparation Example 1 4-(3′,4′-dihydroxyphenyl)-butane-2-one

Zingerone, [4-(3′-methoxy-4′-hydroxyphenyl)-butane-2-one], was dissolvedin dichloromethane, to which 1.0 mol/l boron tribromide solution indichloromethane was then added at −30° C. While stirring, the reactionmixture was gradually heated to a room temperature and allowed to reactfor further2 hours at the temperature. After adding ice water to thereaction mixture, an aqueous 2% sodium hydrogen carbonate solution wasadded. Then, the reaction mixture was extracted with ethyl acetate, andthe ethyl acetate layer thus obtained was dried with anhydrous magnesiumsulfate. Then, the ethyl acetate layer was vacuum condensed to obtainbrown oil which was purified by silica gel chromatography, using amixture of hexane/ethyl acetate =7/3 as a developing solvent. The whitecrystals thus obtained had almost no taste and no odor. Chemicalstructure was confirmed to be 4-(3′,4′-dihydroxyphenyl)-butane-2-one byGC-MS and NMR (see FIGS. 1 and 2).

Preparation Example 2 4-(3′,4′-dihydroxyphenyl)-butane-2-ol

The procedures in preparation Example 1 were repeated except that usewas made of 4-(3′-methoxy-4′-hydroxyphenyl)-butane-2-ol obtained byreducing zingerone with sodium borohydride, instead of zingerone. Thewhite crystals thus obtained had almost no taste and no odor. Chemicalstructure was confirmed to be 4-(3′,4′-dihydroxyphenyl)-butane-2-ol byGC-MS and NMR (see FIGS. 3, 4 and 5).

Method for Determination of Lypolytic Activity

Free fat cells were prepared from epididymis fat tissues of Wister malerats (body weight, 150 to 200 g) using a collagenase solution, accordingto Rodbell's method (M. Rodbell, J.Biol.Chem., 239,375(1964)). The cellswere added to a Hanks' balanced salt solution containing 0.05 μg/ml ofbovine serum albumin, 0.05 μg/ml of norepinephrine and 100/μg/ml of thepresent compound to be tested, and then allowed to react at 37° C. for 1hour. Liberated fatty acids were extracted and quantitated with a copperreagent and a color developing reagent. Lypolytic activity wascalculated according to the following equation.Lypolytic activity (%)=[A/B]×100,wherein

-   -   A: amount of fatty acids in a sample solution, and    -   B: that in a control solution without present compound.

Subcutaneous Fat Decomposition Test

Wister rats (male, 7 to 9 weeks old) were shaved at their bellies. Then,the belly cortex was enucleated together with subcutaneous fat tissuesand mounted on Franz-type diffusion cells with a diameter of 2 cm. Thekeratin held in the upper cell was uniformly coated with 0.5 g of thepresent skin cosmetic composition and the lower cell for thesubcutaneous tissue side was filled with a phosphate-buffer saline at pH7.2. After keeping the cell at 37° C. for 6 hours, an aliquot of thebuffer solution was taken out from the lower cell and glycerol liberatedin the solution was quantitated by an enzyme method with F-kit Glycerol,ex Beringer Manheim Co. For each sample, the quantification was repeatedfive times and data were averaged.

Example 1 and Comparative Example 1

The lypolytic activity was determined on the present lypolysis promoterand raspberry ketone for comparison.

TABLE 1 degree of lypolysis promotion Lypolysis promoter (%) Example 14-(3′,4′- 194.3 +/− 12.4 dihydroxyphenyl)- p < 0.001 butane-2-oneComparative Example 1 Raspberry ketone 142.0 +/− 6.8  p < 0.01

The present lypolysis promoter of Example 1 showed significantly higherlypolytic activity, compared with raspberry ketone of ComparativeExample 1

Examples 2, 3 and Comparative Examples 2 and 3 (Gel Type Skin CosmeticComposition for Reducing Weight)

Parts A and B were separately prepared by mixing and dissolving thesubstances in the amounts as shown in Table 2 in a conventional method.Then Part B was added to Part A with stirring to obtain a gel type skincosmetic composition for reducing weight.

TABLE 2 Com- Com- parative parative Part (wt %) Example 2 Example 3Example 2 Example 3 Part A 4-(3′,4′-dihydroxy 1.0 3.0 — —phenyl)-butane-2-one Raspberry ketone — — 1.0 — Glycerol 10.0 10.0 10.010.0 Carboxyvinyl polymer 0.3 0.3 0.3 0.3 Disodium edetate 0.1 0.1 0.10.1 Purified water balance balance balance balance Diisopropanolamine1.0 1.0 1.0 1.0 Squalane 10.0 10.0 10.0 10.0 Part B Polyoxyethylene (60)0.8 0.8 0.8 0.8 hydrogenated castor oil Carrageenan 3.0 3.0 3.0 3.0Xanthan gum 3.0 3.0 3.0 3.0 Polyvinylalcohol 2.0 2.0 2.0 2.0 Ethanol45.0 45.0 45.0 45.0 Menthol 0.1 0.1 0.1 0.1 Perfume small small smallsmall quantity quantity quantity quantity

The results of the subcutaneous fat decomposition test on the aforesaidgel type skin cosmetic compositions are as shown in Table 3.

TABLE 3 Liberated Glycerol (μmol/ml) Example 2 174.5 Example 3 191.6Comparative Example 2 132.4 Comparative Example 3 60.8

Example 4 and Comparative Examples 4 and 5(In Vivo Test on Obesity byHigh-Calorie Diet)

Each seven ICR mice per group (female, 5-week old at the beginning ofthe test, average body weight of 31 g) were bred for 3 weeks withhigh-calorie diet (Comparative Example 4) or high-calorie diet to which4-(3′,4′-dihydroxyphenyl)-butane-2-one was added (Example 4) or astandard feed (solid standard feed MF, ex Oriental Yeast Co.) for acontrol group (Comparative Example 5). The mice were allowed to freelyintake feed and drinking water, and weighed on the final day of the testperiod. Composition of the feed and the results are as shown in Tables 4and 5, respectively.

TABLE 4 Feed Composition Comparative Comparative Example 4 Example 4Example 5 (Control) wt % wt % Solid standard feed Beef tallow 40  40 MF,ex Oriental Corn starch 10  10 Yeast Co. Granulated sugar 9 9 Mineral*¹4 4 Vitamine*² 1 1 Casein 35  36 4-(3′,4′- 1 — dihydroxyphenyl)-butane-2-one *¹AIN mineral mix, ex ICN Co. *²AIN vitamin mix,

TABLE 5 Results Comparative Example 5 Comparative (Control) Example 4Example 4 Average weight (g) 38.1 38.4 43.2 Weight increment (g) 7.1 7.412.2

Example 5 (Melanogenesis Inhibition Test)

B16 melanoma cells were inoculated in a 12 wells-plastic plate at aconcentration of 2×10⁴/well on MEM (Minimum Essential Medium). After 24hours, the medium was changed to a Theophylline containing medium towhich 4-(3′,4′-dihydroxyphenyl)-butane-2-one was added in theconcentrations shown in Table 6. The cells were cultured for 72 hoursand then treated with 10% TCA and ethanol/diethylether (=1/1). Aftercounting the number of the cells, the cells were dissolved in an aqueous1 mol/l sodium hydroxide solution containing dimethylsulfoxide in aconcentration of 10%. Optical density at 475 nm (OD475 ) of the solutionthus obtained was measured. The amount of the produced melanin per cellwas calculated from OD475 and expressed in percentage relative to theamount observed in the blank sample where cells were cultured on amedium which did not contain 4-(3′,4′-dihydroxyphenyl)-butane-2-one.

TABLE 6 4-(3′,4′- dihydroxyphenyl)- butane-2-one concentration Amount ofmelanin per (μg/l) cell (%) Standard deviation 0 100 11.2 1 97.4 3.4 377.2 2.2 10 62.7 2.5 30 2.2 0.3

There was no difference among the numbers of the cells in the aforesaidconcentration range of the present compound.

Example 6 (Anti-Oxidation Test)

To 1 ml of methyl linolate, 0.005g of the present compound was added,which was then irradiated with UV light with a UV light irradiationapparatus, M-DMR, ex Toshiba Co.. The amount of peroxides formed byoxidation of methyl linolate was determined according to a methoddescribed in Akasaka et al., Bioscience/Biotechnology/Biochemistry, Vol.58, 396(1994), using diphenyl-1-pyrenylphosphine as a fluorescentlabeling agent. Comparative test on raspberry ketone was made in thesame manner as above. The results are as shown in Table 7.

TABLE 7 UVB 10 (J/cm²) UVB 30 (J/cm²) Raspberry ketone 30.2 42.54-(3′,4′-dihydroxyphenyl)- 1.6 3.7 butane-2-one

Examples 7 to 12

Skin lotion were prepared from the components as shown below and inTable 8.

Parts Amount (wt %) (A) Ethanol 10.0 Monolauric acid 5.0polyoxyethylene(20) sorbitan Dibutylhydroxytoluene 0.01 Perfume 0.05 (B)The present compound described in Table 8 (C) Glycerol 5.0 Xanthan gum0.1 Hydroxyethylcellulose 0.1 Purified water balance

TABLE 8 Sample Amount (wt %) Example 7 4-(3′,4′- 3.0 dihydroxyphenyl)-butane-2-one Example 8 4-(3′,4′- 0.5 dihydroxyphenyl)- butane-2-oneExample 9 4-(3′,4′- 0.01 dihydroxyphenyl)- butane-2-one Example 104-(3′,4′- 3.0 dihydroxyphenyl)- butane-2-ol Example 11 4-(3′,4′- 0.5dihydroxyphenyl)- butane-2-ol Example 12 4-(3′,4′- 0.01dihydroxyphenyl)- butane-2-ol

Preparation Method

Part B was homogeneously dissolved in Part C, to which Part A was addedwith stirring to be dispersed homogeneously. The product thus obtainedwas poured in a container.

Examples 13 to 18 (Skin Cream)

Skin creams were prepared from the components shown below and in Table9.

Part Amount (wt %) (A) Glycerol monostearate 2.0 Beeswax 1.0 Monooleicacid polyoxyethylene(6) 1.0 sorbitan Vaseline 4.0 Liquid petrolatum 12.0(B) The present compound described in Table 9 (C) SodiumN-stearoyl-L-glutamate 5.0 Carrageenan 0.3 Methylparaben 0.1 Purifiedwater balance

TABLE 9 Sample Amount (wt %) Example 13 4-(3′,4′- 3.0 dihydroxyphenyl)-butane-2-one Example 14 4-(3′,4′- 0.5 dihydroxyphenyl)- butane-2-oneExample 15 4-(3′,4′- 0.01 dihydroxyphenyl)- butane-2-one Example 164-(3′,4′- 3.0 dihydroxyphenyl)- butane-2-ol Example 17 4-(3′,4′- 0.5dihydroxyphenyl)- butane-2-ol Example 18 4-(3′,4′- 0.01dihydroxyphenyl)- butane-2-ol

Preparation Method

Part A and a mixture of Components B and C were separately heated to 80°C. to make homogeneous solutions. Then, Part A was added to the mixtureof Parts B and C and emulsified. The emulsion thus obtained was cooledto 30° C. with stirring.

Example 19 (Chewing Gum)

Chewing gum with the following composition was prepared.

wt % Gum base 20 Maltitol 73.5 Reduced glutinous starch syrup 4 Appleflavor 0.5 Garcinia Cambogia Extract*¹ 14-(3′,4′-dihydroxyphenyl)-butane-2-one 1 *¹Garcinia Cambogia Extract,Citrimax HCA-500-F (trade name), ex Interhealth Nutraceutical Inc.,containing 47.5% of hydroxycitric acid (HCA).

Example 20 (Sweet Tablets)

Sweet tablets with the following composition was prepared.

wt % Sorbitol 72.9 Sucrose ester of fatty acid 4 Raspberry flavor 0.1Garcinia Cambogia Extract 3 4-(3′,4′-dihydroxyphenyl)-butane-2-one 10

1. A food or drink composition comprising a food additive including acompound represented by the following formula (1)

wherein R¹ and R² are both hydrogen.
 2. The food or drink composition inaccordance with claim 1, wherein the compound is present in an amount offrom 0.01 to 10.0 wt % based on the weight of the composition.
 3. Thefood or drink composition in accordance with claim 2, wherein thecompound is present in an amount of from 0.01 to 3.0 wt % based on theweight of the composition.
 4. The food or drink composition inaccordance with claim 1, wherein the food composition is in a formselected from the group consisting of chewing gum, chocolate, candy,gummy jelly, soup, ice cream, noodle and bakery product.
 5. The food ordrink composition according to claim 2, wherein the food composition isin a form selected from the group consisting of chewing gum, chocolate,candy, gummy jelly, soup, ice cream, noodle and bakery product.
 6. Thefood or drink composition according to claim 3, wherein the foodcomposition is in a form selected from the group consisting of chewinggum, chocolate, candy, gummy jelly, soup, ice cream, noodle and bakeryproduct.
 7. The food or drink composition according to claim 1, whereinthe compound is present in an amount of from 0.001 to 20 wt % based onthe weight of the composition.
 8. The food or drink compositionaccording to claim 7, wherein the food composition is in a form selectedfrom the group consisting of chewing gum, chocolate, candy, gummy jelly,soup, ice cream, noodle and bakery products.
 9. A method for preparing afood or drink composition comprising incorporating a food additive intothe food or drink composition, wherein the food additive comprises thecompound of formula (1)

where R¹ and R² are both hydrogen.
 10. The method in accordance withclaim 9, wherein the compound is incorporated in an amount of from 0.001 to 20 wt % based on the weight of the composition.
 11. The method inaccordance with claim 10, wherein the compound is incorporated in anamount of from 0.01 to 10.0 wt % based on the weight of the composition.12. The method in accordance with claim 10, wherein the compound isincorporated in an amount of from 0.01 to 3.0 wt % based on the weightof the composition.
 13. The method in accordance with claim 9, whereinthe food composition is in a form selected from the group consisting ofchewing gum, chocolate, candy, gummy jelly, soup, ice cream, noodle andbakery product.
 14. The method according to claim 10, wherein the foodcomposition is in a form selected from the group consisting of chewinggum, chocolate, candy, gummy jelly, soup, ice cream, noodle and bakeryproduct.
 15. The method according to claim 11, wherein the foodcomposition is in a form selected from the group consisting of chewinggum, chocolate, candy, gummy jelly, soup, ice cream, noodle and bakeryproduct.
 16. The method according to claim 12, wherein the foodcomposition is in a form selected from the group consisting of chewinggum, chocolate, candy, gummy jelly, soup, ice cream, noodle and bakeryproduct.
 17. The method in accordance with claim 9, wherein the compoundis incorporated in an amount of at least 1.0 wt. % based on the weightof the composition.
 18. The method in accordance with claim 17, whereinthe compound is incorporated in an amount of at least 3.0 wt. % based onthe weight of the composition.
 19. A food or drink compositioncomprising the compound represented by the following formula (1) in anamount of from 0.01 to 10.0 wt %

where R¹ is hydrogen and R² is glucose residue.
 20. The food or drinkcomposition in accordance with claim 1, wherein the compound is presentin an amount of at least 1.0 wt. % based on the weight of thecomposition.
 21. The food or drink composition in accordance with claim20, wherein the compound is present in an amount of at least 3.0 wt. %based on the weight of the composition.